Solid-state light emitters, such as light-emitting diodes (LEDs) and laser diodes, have several advantages over using more traditional arc lamps during curing processes, such as ultraviolet (UV) curing processes. Solid-state light emitters generally use less power, generate less heat, produce a higher quality cure, and have higher reliability than the traditional arc lamps. Some modifications increase the effectiveness and efficiency of the solid-state light emitters even further.
Most solid-state light emitters have a housing within which light-emitting elements, such as LEDs and laser diodes, are positioned. The light-emitting elements emit light through a window of the housing onto a substrate to cure a light-activated material to the substrate. The windows in these conventional housings emit light toward the substrate in a single direction because the windows are flat and one-dimensional. For example, a solid-state light emitter is positioned directly above a substrate with a light-activated material to cure the material to the substrate when light emitted from the emitter is directed toward the substrate. The windows used in these conventional light emitters are flat front glass and extend along some portion of the housing along a single plane that is usually facing or perpendicular to the substrate on which the curing occurs. Oftentimes, however, the surface area of the substrate being cured is larger than the width of the window and the light output uniformity decreases severely at the edges of these flat front glass windows, which causes decreases in the surface area of the substrate that receives a quality cure, the efficiency of the curing process, and the ability to stack solid-state light emitters end-to-end.
Most solid-state light emitters do not address the light output uniformity challenges and result in a lower quality cure with less efficiency and a decreased effectiveness of stacking solid-state light emitters end-to-end.